Thin wall package for use within a reusable cartridge

ABSTRACT

A package assembly is provided for use within a reusable cartridge for dispensing at least one component. The package assembly includes a container with a thin, flexible membrane wall with an open end, and a front outlet to which the open end of the membrane container is secured by a ring-shaped sealing element. This membrane container outlet end allows conventional filling of the container and a perfect seal at the front outlet.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

[0001] This application is a US national stage application of PCTApplication PCT/EP99/07558, filed Oct. 10, 1999, claiming priority toEuropean Application EP 988 11 014.4, filed Oct. 8, 1998.

BACKGROUND OF THE INVENTION

[0002] The use of two component cartridge systems is well known for thestorage, metering and mixing of two component reactive chemical systemssuch as epoxies, polyurethanes, acrylics, silicones, polysulfides andpolyesters. It is also well known that, for environmental reasons,cartridge systems including sausage type packages with thin plastic/foillaminate membrane walls are used to contain such chemicals. Thesepackages are fitted within and supported by a cartridge like structurewhile the contents are dispensed. When depleted, the sausage typepackages may be disposed of, while the whole (or majority) of thesupporting cartridge structure can be reused.

[0003] It is within this field of sausage type package use that certainproblems are seen to arise. For example, U.S. Pat. Nos. 5,332,122 and5,501,368 teach containers for flowable substances. These containersrequire packages fabricated from flexible plastic foil/laminate sheets.For a given package, the flexible plastic foil/laminate sheet is foldedto form a tube and then partially overlapped and welded together suchthat, along the weld length, the now double layer seam is thicker andless flexible than the rest of the package wall and is subject topotential leakage due to weld failure. Moreover, the aforementionedcontainer tube fabrication takes place as the first stage of a complexand continuous fabrication, filling and closing process, the processcontinues after the initial closing of the tube with the immediatechemical filling of the tube as the second stage. The third stageinvolves the dividing off and closing of the, now, filled tube intovolumetrically controlled lengths. At the division points, the filledtube diameter is reduced all the way to the tube axis, which results inconsiderable wrinkling of the tube wall prior to being closed by acrimped ring. Such crimped ring closures often fail to achieve aneffective seal due to the incompressibility of the membrane and of thewrinkled overlaps which, themselves, tend to form leak paths underpressure. For the same reasons, the necessary sealing of the wrinkledtube wall against a front outlet is another failure area.

[0004] In addition, at a time just prior to the package use and after ithas been placed within a reusable cartridge support structure, thepackage outlet end must be opened. This is done by cutting behind thecrimped ring closure of the package. This opening of the package outletend allows the package to settle within the reusable cartridge,adjusting its outer shape to conform to that of the internal diameter ofthe supporting structure. In doing so, air is induced into the package,particularly with lower viscosity chemicals. Thus, as air within ametering package causes the content to be non-hydraulic and thereforecompressible, both the start and the stop of each of the two meteredflows go out of synchronization relative to each other, which can resultin an “off ratio” mixture when being processed through a static mixer.Furthermore, at the end of the discharge stroke, this can also lead toan unacceptable residual volume of chemical left within the center ofthe collapsed package due to incomplete compaction as a result of themembrane having been scraped off the outer supporting structure wall,folded and compacted in a more or less ring shaped fashion.

[0005] Alternatively, if a fabricated membrane container with alongitudinal seam is used for a package, problems arise in particular atthe outlet of the package. One proposal, according to U.S. Pat. No.5,647,510, provides, at the outlet end, an outlet piece to which thestraight end of the membrane container wall is adhered. This adhesionprocess, however, is difficult to achieve in a leak proof and reliablefashion.

SUMMARY OF THE INVENTION

[0006] Starting from the aforementioned prior art, it is an object ofthe present invention to provide a thin wall membrane package whichovercomes the above mentioned drawbacks, and provides a proper sealingand closure of the outlet end.

[0007] A further object is to avoid the problems arising from thefabricated sausage type package with longitudinal seams and a rear endclosure. Thus, according to one aspect of the present invention, apackage assembly is provided including an integrally formed, uniform andseamless thin flexible membrane wall container so as to avoid any chanceof seam joint or rear end closure failure.

[0008] A further object is to provide for a package with easy handlingand assembling properties and which improves, in particular, theattachment of a dynamic mixer.

[0009] Above all, another aspect of the present invention is directed atimproving and/or eliminating the highly complex and necessarily combinedfabrication and filling process, which entails high initial capitalinvestment and is only economically viable for long production runs thatcan absorb the high “setting up” costs prior to each production run.Hence, an environmentally advantageous package is proposed with themajor advantages of being fillable by existing conventional cartridgefilling methods, yet avoiding the entrapment of air within the liquidchemical content.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Preferred embodiments of the invention will now be described indetail by reference to the accompanying drawing. Wherever possible, thesame reference numbers will be used throughout the drawings to refer tothe same or like parts.

[0011]FIG. 1 shows a longitudinal cross-section of a package accordingto a first embodiment of the invention;

[0012]FIG. 2 shows a longitudinal cross-section of a package accordingto a second embodiment of the invention;

[0013]FIG. 3 shows the package of FIG. 1 prior to filling;

[0014]FIG. 4 shows the package of FIG. 3 after filling;

[0015]FIG. 5 shows a longitudinal cross-section of a cartridge assemblywith two packages of FIG. 4 in two different stages of dispensing;

[0016] FIGS. 6-8 each show a longitudinal cross-section of threedifferent package assembly closures according to various embodiments ofthe present invention;

[0017]FIG. 9 shows a variant of the cartridge assembly of FIG. 5according to an embodiment of the present invention; and

[0018]FIG. 10 shows another cartridge assembly according to anembodiment of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0019]FIG. 1 shows a longitudinal cross-section of a bottle shapedpackage assembly 1 having an integrally formed and seamless thinflexible wall 2 with an open neck end 3 passing through the inside ofthe tube 4 of a front outlet 5, the flexible wall 2 being folded backover the front outside diameter of that tube 4. A sealing ring 6, withlips 7 and 8 for sealing against the cartridge outlet, is fitted overthe flexible wall 2 on the inside and outside of the tube 4, the sealingring 6 being formed to receive a separate sealing plug 9.

[0020] It follows from the above that the package is made bottle shapedso as to essentially match the internal shape of a supporting structurebefore its insertion, such that it minimizes the necessary adjustment ofthe external shape of the package to that of the supporting structurewhich could otherwise lead to air induction into the package when thepackage is inserted inside the supporting structure and opened prior todispensing. Furthermore, in comparison with the “state of the art”package which has two closed off ends, this aspect of the inventionproposes a package assembly with only one closable open neck end, theopen neck end having a reduced diameter with the advantage of the entirepackage wall having no wrinkles whatsoever.

[0021] Another aspect of the invention for a fabricated sausage typepackage according to FIG. 2, proposes the use of a compressible plug,rod or mushroom like device held within the closed wrinkled wall endsuch that the closure means, for instance a crimped ring, creates andmaintains a compressive tension, the compressible device itself actingas an expanding and self adjusting sealing bung.

[0022]FIG. 2 shows a longitudinal cross-section of a package assembly 11having a fabricated thin flexible wall 12 with two open ends, one beingclosed by a crimped ring 13 against a central compressible mushroomshaped device 14. At the front of the package assembly 11, the open neckend 15 passes through the inside of the tube 4 of the front outlet 5 andis folded back over the front outside of tube 4 with a sealing ringfitted as similarly shown in FIG. 1.

[0023] According to the characteristics of the chemicals to be stored inthe containers, the membrane container wall comprises one or more layersof the same material or of different materials.

[0024]FIG. 3 shows a longitudinal cross-section of a bottle shapedpackage assembly 1, as shown in FIG. 1, with the rear part of theflexible membrane wall 2 having been folded over within itself and“outside-in” down to the inside of the front outlet 5 by a plunger 17.This collapsed bottle shaped package within a rigid structure 60 is thusnow ready for filling, the air previously contained within the packageassembly having been evacuated by vacuum.

[0025]FIG. 4 shows a longitudinal cross-section of the same packageassembly 1 as in FIG. 3 but after filling with chemical 16, andplugging.

[0026]FIG. 5 shows a longitudinal cross-section of a cartridge assembly18 which retains package assemblies 1A and 1B with chemical contents16A, 16B within cylinders 20A, 20B and sealing those package assemblies1A and 1B against cartridge outlet 21 via the sealing means 6A, 6B andlips 7, 8. Package assembly 1A is shown with the driven piston 22A, withlip 23A, attached to the back of the package assembly 1A and driveplunger 24A, with drive rod 25A, ready for forward movement. Packageassembly 1B is shown in a partly dispensed state with the driven piston22B, with lip 23B, having been pushed down within the cylinder 20B bythe drive plunger 24B and drive rod 25B such that the package assembly1B has been turned “outside in” within itself while displacing thechemical content 16B via the cartridge outlet 21.

[0027]FIG. 6 shows a longitudinal cross-section of a variation of apackage assembly closure embodiment in the form of a package assemblysealing ring 6, serving as a retaining means for the sealing andsecuring means of the membrane in the form of an O-ring 26 on theoutside diameter of tube 4 which is provided with a groove 36. Theretaining ring 6 is also provided with a single sealing lip 8 and isclosed off by a sealing plug 9.

[0028]FIG. 7 shows a similar package assembly closure embodiment as FIG.6, with the exception of the inner part 39 of sealing ring 28 having anattached burstable or pierceable diaphragm 33. It is evident that thesealing and securing O-ring stands for any appropriate sealing element.

[0029]FIG. 8 shows a longitudinal cross-section of a variation of thepackage assembly closure embodiment of FIG. 6, in the form of a sealingring 34 incorporating a spring loaded valve 41 which facilitates airfree filling of the package and is opened by a pin 35 attached to thecartridge outlet.

[0030]FIG. 9 shows one side only of a longitudinal cross-section of acartridge assembly 18 similar to that shown in FIG. 5, in that itretains the package assembly 1A with chemical contents 16A withincylinder 20A but with the variation that the neck of the membrane 2A issealed and secured on the outside of the tube 4 of the front outlet 5Aby O-ring 26 within an external groove 31, the O-ring 26 beingcompressed against the cartridge outlet 21 so as to form a ring sealingmeans between that cartridge outlet 21 and the membrane 2A. Also, theinside of the tube 4 is fitted with a closure having a burstablediaphragm 33 as shown in FIG. 7.

[0031]FIG. 10 shows a longitudinal cross-section of one side of acartridge assembly 58 which retains package assembly 42A with chemicalcontents 16A within the cartridge cylinder 43A, the full diameter outletend of container membrane 44 being secured and sealed between O-ring 45and the O-ring groove 46 within the outer periphery 49 of the frontoutlet 47, the securing O-ring 45 being retained by the retaining ring48 against the outer periphery of the front outlet 47. In addition,under operating conditions, the wall 44E of the membrane 44 is furthersealed by the action of the pressure actuated lip 59. Lip 59 can eitherpress on the outlet end of cartridge cylinder wall 43A or on itscontinuation, the wall of retaining ring 48.

[0032] The tube 51 of the front outlet 47 is closed by sealing ring 52via O-ring 53 in groove 54, the end 55 of the inner part 56 of sealingring 52 having a burstable diaphragm 33 attached. The package assembly42A is shown sealed against the cartridge outlet 57 via the sealing ringmeans 52 with lips 7A, 8A.

[0033] It follows that a sealed outlet closure is achieved regardless ofwhether the flexible membrane wall is seamless or not, or whether thecontainer is bottle-shaped or not. The proposed method and the closuremeans allow also the filling of the container without any air inclusion.

[0034] The embodiments of FIGS. 5, 9 and 10 all show a cartridge outlet21 or 57 made in one piece, to which the individual front outlets 5, 5A,or 47 respectively are attached. This improves the handling and theassembly of such packages considerably, and also enables the easy useof, and attachment of a dynamic mixer.

[0035] The embodiment with a sealing ring incorporating a spring loadedvalve facilitates the container to be collapsed and evacuated, tomaintain evacuation prior to air free filling, to maintain the filledcondition without leakage, and allows for trouble free insertion intothe supporting cartridge structure and connection to the cartridgeoutlet prior to use.

1. A reusable cartridge assembly for dispensing at least one component,comprising at least one cartridge cylinder (20A, 20B, 43A) having arigid wall, a cartridge outlet and a package assembly (1A, 1B, 42A), thepackage assembly comprising a container having a thin, flexible membranewall with an open end, characterized in that the package assembly (1,1A, 1B, 11, 42A) further comprises a front outlet (5, 5A; 47) to whichthe open end (3, 15, 44E) of the flexible membrane wall (2, 2A, 12, 44)is secured by a ring-shaped sealing element (6, 6A, 6B, 34) or by aring-shaped sealing element (26, 45) retained by a retaining means (6,28, 48).
 2. A reusable cartridge assembly for dispensing at least onecomponent, comprising at least one cartridge cylinder (20A, 20B, 43A)having a rigid wall, a cartridge outlet and a package assembly (1A, 1B,42A), the package assembly comprising a container having a thin,flexible membrane wall with an open end, characterized in that the thin,flexible membrane wall (2, 2A, 44A) of the container (1, 1A, 1B, 42A, isintegrally formed and seamless.
 3. A cartridge assembly according toclaim 1, characterized in that the container has a fabricated, thin,flexible membrane wall (12) with a closed end (13, 14) and an open end(15).
 4. A cartridge assembly according to claim 2, characterized inthat the open end (3, 44E) of the membrane container (2, 2A, 44A) issecured to the front outlet (5, 47) by a ring-shaped sealing element (6,6A, 6B, 34) or by a ring-shaped sealing element (26, 45) retained by aretaining means (6, 28, 48).
 5. A cartridge assembly according to any ofclaims 1 to 4, characterized in that the membrane container is made withan open neck end (3, 15), the external shape of which essentiallymatches the internal shape of a supporting structure.
 6. A cartridgeassembly according to claim 5, characterized in that the membranecontainer is bottle shaped and has a closure element (9, 33, 41).
 7. Acartridge assembly according to claim 5 or 6, characterized in that thefront outlet (5) of the package comprises a tube (4) having as a ringshaped sealing element a sealing ring (6, 6A, 6B, 28, 34) fitted aroundthe outlet end of the tube for attaching and sealing the open neck end(3, 15).
 8. A cartridge assembly according to any of claims 1 to 6,characterized in that the open neck end (3, 15) of the membrane wall issecured in a groove (31, 36) at the outer diameter of the front outlettube (4) by a ring shaped sealing element (26) retained by the sealingring (6, 28) or by the bore of the cartridge outlet (21).
 9. A cartridgeassembly according to any of claims 1 to 4, characterized in that theend of membrane wall (44E) is secured in a groove (46) at the peripheryof the front outlet (47) by the sealing element (45) retained by theretaining ring (48).
 10. A cartridge assembly according to claim 9,characterized in that the front outlet (47) comprises a sealing lip(59), sealing the membrane wall (44) against the cartridge wall (43A) orthe sealing ring (48).
 11. A cartridge assembly according to claim 9 or10, characterized in that the front outlet (47) comprises a tube (51)and a sealing ring (52) fitted around the tube having a closure element(9, 33, 41).
 12. A cartridge assembly according to any of claims 1 to11, characterized in that the sealing ring (6, 6A, 6B, 28, 34, 52) isprovided with at least one sealing lip (7, 7A, 8, 8A) at its outerdiameter.
 13. A cartridge assembly according to claim 2, characterizedin that the integral membrane container has at least one additionalmembrane layer.
 14. A cartridge assembly according to any of claims 1 to13, characterized in that the front outlet tube (4, 51) comprises aclosure having a burstable or pierceable diaphragm (33).
 15. A cartridgeassembly according to any of claims 1 to 14, characterized in that thefront outlet tube (4, 51) is closed by a sealing plug (9).
 16. Acartridge assembly according to any of claims 1 to 14, characterized inthat the front outlet tube (4, 51) is closed by a self closing valve(41).
 17. A cartridge assembly according to any of claims 1, 3, 5 to 15,characterized in that the closed back end of the membrane container (12)has, at it's center, a compressible plug (14) and a closure element (13)over it's outer diameter.
 18. A cartridge assembly according to claim17, characterized in that the compressible plug (14) has an increaseddiameter on at least one of it≡s ends.
 19. A cartridge assemblyaccording to any one of claims 1 to 18, characterized in that thecartridge outlet (21, 57) is made in one piece for receiving theindividual front outlets (5, 5A, 47) of the package assembly.
 20. Acartridge assembly according to any one of claims 1 to 19, characterizedin that the sealing lips (7, 7A, 8, 8A) of the sealing ring (6, 6A, 6B,28, 34, 52) or the sealing element (26) are sealing within the bore ofthe cartridge outlet (21, 57).
 21. A cartridge assembly according to anyof claims 1 to 20, characterized in that the cartridge assembly furthercomprises a driven piston (22A, 22B), the piston and the piston sideends of the wall of the cartridge cylinder being arranged such that themembrane container is turned “outside in” by the action of the piston.22. A cartridge assembly according to any of claims 1 to 21,characterized in that the cartridge outlet (21, 57) comprises a pin (35)for opening the self closing valve (41).
 23. A method for filling thepackage assembly according to any of claims 1-22, characterized in that,prior to filling, the membrane container having an open front end isturned “outside in”, then vacuum is applied at the outlet end forcomplete air evacuation, whereupon the membrane container package isfilled with the chemical content free of air and closed by the outletclosure elements.